A Dynamic Relative Positioning Method Based on LEOs-SOP/JTIDS/INS Combination

To address the issue of limited relative positioning accuracy caused by insufficient measurement precision of low earth orbit satellite signals of opportunity (LEOs-SOP), an LEOs-SOP/joint tactical information distribution system (JTIDS)/inertial navigation system (INS) integrated relative positioning framework is established. Building on the relative positioning of the LEOs-SOP/INS combination, the framework integrates JTIDS-provided relative distance measurements between carriers to further enhance the relative positioning accuracy between them. To address the issue that Iridium pseudorange rate noise follows a Gaussian distribution while pseudorange noise aligns with a Laplacian distribution, this study builds upon the maximum correntropy error state filter (MCESF). Gaussian kernel functions are used to weight the pseudorange rate measurement noise matrix, and Laplacian kernel functions are applied to weight the pseudorange measurement noise matrix, thereby enhancing the robustness of the system. Simulation and experimental results demonstrate that the proposed LEOs-SOP/JTIDS/INS integrated relative positioning method improves positioning accuracy by approximately 30% compared to the traditional LEOs-SOP/INS relative positioning method, achieving relative positioning performance better than 15 m. Additionally, the proposed robust filtering method effectively mitigates the impact of anomalous measurements from LEOs-SOP on relative positioning, enhancing positioning accuracy by approximately 20% compared to conventional robust filtering methods.